The present invention relates to an image forming unit detachably mounted to a main body, and relates to an image forming apparatus having the image forming unit.
An image forming unit of an image forming apparatus includes a photosensitive drum that bears a latent image, and a developing roller that contacts the photosensitive drum for developing the latent image using a toner. The image forming unit further includes a supplying roller that contacts the developing roller for supplying the toner (supplied by a toner tank) to the developing roller, and an agitating member that agitates the toner for preventing agglomeration of the toner. These members are rotated by a driving source provided in the image forming apparatus. The agitating member is provided in contact with or in the vicinity of the supplying roller, and rotates in one direction to supply the toner to the supplying roller (see, for example, Japanese Laid-open Patent Publication No. 2005-172842).
In this regard, a conventional image forming unit has an agitating member in the form of a crank and rotatable about a center thereof. With such a configuration, the agitating member has a relatively small rotation radius, and can agitate the toner only in a small area. Therefore, agglomeration of the toner may occur outside the small area. In such a case, the toner may not be sufficiently supplied to the supplying roller. As a result, the amount of the toner supplied by the supplying roller to the developing roller decreases, and image defects such as image blurring may occur, i.e., image quality may be deteriorated.
Further, it is conceivable to provide a plurality of agitating members for agitating the toner in a large area. However, such a configuration may be subjected to spatial limitation, and subjected to an increase in cost.